The project had been in limbo since 2007, passing from J.J. Abrams to Ron Howard in 2010 before ultimately landing in the hands of director Nikolaj Arcel. Post-production rumors further raised red flags and, sure enough, The Dark Tower has proven a movie that will both disappoint King’s faithful and perplex newcomers to the tale.

The Dark Tower story spans eight books. The Dark Tower movie spans 95 minutes. Rather than shoot for a direct adaptation of any one book, the filmmakers opted for a mishmash of events depicted at various points in the epic and then took additional liberties.

Obviously any film adaptation is going to require some tweaking and paring, but what we get here is a crude patchwork of what is, in writing, a vast mythology—and the end product is a hurried and shallow simulacrum that fails to stand on its own.

The film version tells the story of Roland Deschain (Idris Elba) through the eyes of a boy named Jake Chambers (Tom Taylor). Jake has been plagued by nightmares since his father died: visions of another world, a Man in Black (Matthew McConaughey), and the gunslinger Roland, an alternate-universe cowboy-knight sworn to protect the Dark Tower from falling. When some evil goons come to kidnap Jake, he finds a way to cross dimensions and runs into Roland, who’s now on a quest to kill the the Man in Black.

There’s not much of anything worth seeing here. The story comes out like word vomit. The CGI looks years behind. The action sequences are mostly unimaginative. Matthew McConaughey dials his McConaugheyness to 11 even though he’s playing an evil sorcerer, which is a constant distraction.

The only enjoyable part of the film is Idris Elba, who is so supremely talented he could play a shoe in a movie and it would somehow be badass and compelling. Here he imbues Roland with both an awesome power and a reserved helplessness that gives at least some nuance to a world of one-dimensional characters. The only thing he doesn’t quite nail is Roland’s obsession, but that has more to do with the movie’s overall shortcomings than it does with Elba’s performance. And Elba’s strong portrayal is yet another great fuck-you to adaptation purists who believe a character originally written as white, like Roland Deschain, can’t be anything other than white.

It’s a shame The Dark Tower couldn’t be more. There’s so much source material from which to draw, so many ambitious ideas to explore had the movie been reined in. We could’ve had a Harry Potter-type franchise here. But given how poorly The Dark Tower was executed, it’d be a shock to see anything else come of it.